Looks like Macca found some time whilst recording his Kisses album to record his own version of "The Christmas Song" with Diana Krall's band. The song is planned to appear on a forthcoming Christmas album titled Holidays Rule. You can listen to it here:

I find McCartney's version of "The Christmas Song" to be a quaint little cover. There's nothing really remarkable about it, but it's a pleasant reading of a Christmas standard. Should have no problem fitting in with my other Christmas music collection.